Enhanced mechanical properties of Ni62Nb38 bulk metallic glasses by Ta substitution

By substituting Ta for Nb in a binary Ni62Nb38 bulk metallic glass (BMG), ternary Ni62Nb38 − xTax (x = 5-35) BMGs were fabricated by copper mold suction casting. The present NiNbTa BMGs not only have good glass forming ability (GFA), but also have combinations of both high strength and relatively-large plastic strains, which are superior to the binary Ni62Ni38 BMG and some other Ni-Nb-based BMGs. The Ni62Nb18Ta20 BMG has fracture strength of about 3.2 GPa and a plastic strain of about 1.36%. The enhancement of the mechanical properties of the NiNbTa BMGs is related to the change of the liquid behavior and glass forming ability by Ta-substitution.